1. Field of the Invention
This invention relates generally to a process and system to treat domestic animal manure, such as pigs and swine, both liquid and solid, to enhance the environment so that the residual treated solid and liquid waste are free from odors, can be returned back to the environment, and can be used as productive elements of the environment and, specifically, to a process and system that treats pig and swine liquid and solid manure to eliminate odors, water contamination, and soil contamination, with the safe return of these byproducts back into the environment at low cost.
2. Description of the Prior Art
The creation of large farms for raising domestic animals at the commercial level in large numbers, such as cows, chickens, pigs, and swine, has created an increased concern environmentally over the animal waste products, typically liquid and solids, created by such large domestic production of animals. Typical environmental concerns which are each related but different in result include air contamination caused by the odors produced from the waste, ground water and stream contamination from runoffs at the waste site, and soil contamination, particularly for agricultural purposes, resulting from the large volume of waste. Therefore, organic animal waste sludges have become a tremendous environmental problem throughout the United States and throughout the world.
The prior art discloses processes for trying to solve the problem of sludge and the environment. U.S. Pat. No.: 4,193,206 issued Mar. 18, 1980 to Maffet discloses processes for drying sewage sludge and filtering water. As shown, wet sewage sludge is dried in either a thermal drying zone or a mechanical dewatering zone comprising a cylindrical chamber with a porous wall. A plasticizer is added to the dry sludge. Overall, the system is rather complicated and has several additional processes when compared with applicant's invention. U.S. Pat. No.: 4,270,279 issued Jun. 2, 1981 to Roediger discloses a method for drying, and sterilizing sewage sludge. Basically the sludge is dried and broken into small pieces and covered with quicklime. U.S. Pat. No.: 4,295,972 issued Oct. 20, 1981 to Kamei discloses a method for treating water containing waste. The method includes adding calcium oxide for preliminary drying and granulating the mixture. U.S. Pat. No. 5,013,458 issued May 7, 1991 to Christy, Sr. et al. discloses a process and apparatus for pathogene reduction and waste. The method includes using hydration reaction by elevating the pH of the sludge for releasing heat. None of the methods disclosed in these patents shows the simple and efficient treatment of sludge as disclosed by applicant's method which includes economical steps of dewatering the sludge and water filtration using membranes.
Thus, when looking at agricultural waste, the increasing production of the waste, such as pig and swine production and their waste products, presents a large problem for both farming soils and the natural environment, which includes streams, water tables, and soils.
Although this specific invention is directed toward pig and swine liquid and solid manure waste products for the treatment of odor, and liquid and solid waste contamination, the invention may have other applications for the treatment of agricultural, industrial, and municipal sludges also.
The overall invention, both the method and system, deals with two major phases. Phase one involves the separation of liquids from the sludge or animal waste product, be it pig manure or swine manure, to get the driest sludge available, while separating the water for further treatment. This greatly reduces the volume of the sludge from the first phase once a good portion of the liquid has been removed.
The second phase involves the treatment of water and liquid removed from the pig and swine waste sludge. This water is treated by a pressure-driven membrane separation technology so that it is clean enough environmentally to return to the natural water supply. One of the important features of the invention is that it limits the use of additional chemicals that have been traditionally used to treat sludge to further prevent environmental harm. Thus, the invention does not use chemicals, such as chlorine, to accomplish the results.